Definitions

Tabula Rasa: (Latin for: a blank tablet). A phrase used by John Locke (1632-1704) to describe the state of the human mind at birth. His contention was that innate a priori knowledge is a fiction and that only experience can furnish the mind with ideas.

A Dictionary Of Philosophy. Second edition. (Pan Books 1984). Page 349.

A priori: Locke and Hume argued that all our ideas or concepts are derived from experience. Against this, others, such as Plato and Leibniz, have contended that there are some notions of great importance - for instance, substance, equality, cause, or likeness and difference - that could not have been so derived; these notions are on this account rated a priori concepts. It has also been argued, above all by Kant, that some such a priori concepts are presupposed by the very possibility of experience...

Ibid. Page 16.